Sample Preparation of Illicit Drugs for FT-IR Microspectrophotometry

The hemicellulose composition of a pulp significantly affects its chemical and physical properties and thus represents an important process control variable. However, complicated steps of sample preparation make standard methods for the carbohydrate analysis of pulp samples, such as high performance liquid chromatography (HPLC), expensive and time-consuming. In contrast, pulp analysis by attenuated total internal reflection Fourier transform infrared spectroscopy (ATR FT-IR) requires little sample preparation. Here we show that ATR FT-IR with discrete wavelet transform (DWT) and standard normal variate (SNV) spectral preprocessing offers a convenient means for the qualitative and quantitative analysis of hemicelluloses in bleached kraft pulp and alkaline treated kraft pulp. The pulp samples investigated include bleached softwood kraft pulps, bleached hardwood kraft pulps, and their mixtures, as obtained from Canadian industry mills or blended in a lab, and bleached kraft pulp samples treated with 0–6% NaOH solutions. In the principal component analysis (PCA) of these spectra, we find the potential both to differentiate all pulps on the basis of hemicellulose compositions and to distinguish bleached hardwood pulps by species. Partial least squares (PLS) multivariate analysis gives a 0.442 wt% root mean square errors of prediction (RMSEP) for the prediction of xylan content and 0.233 wt% RMSEP for the prediction of mannan content. These data all support the idea that ATR FT-IR has a great potential to rapidly and accurately predict the content of xylan and mannan for bleached kraft pulps (softwood, hardwood, and their mixtures) in industry. However, the prediction of xylan and mannan concentrations presented a difficulty for pulp samples with modified cellulose crystalline structure.

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Fourier transform infrared spectroscopy of dental unit water line biofilm bacteria

Spectroscopy An International Journal ◽

10.1155/2009/892569 ◽

2009 ◽

Vol 23 (3-4) ◽

pp. 175-189 ◽

Cited By ~ 1

Author(s):

Iram Liaqat

Keyword(s):

Fourier Transform ◽

Sample Preparation ◽

Broad Band ◽

Fourier Transform Infrared ◽

Achromobacter Xylosoxidans ◽

Absorption Bands ◽

Biofilm Growth ◽

Acridine Orange Staining ◽

Ft Ir ◽

Atr Spectroscopy

Fourier transform-infrared (FT-IR) spectroscopy has become an important tool for rapid analysis of complex biological samples. The infrared absorbance spectrum could be regarded as a “fingerprint” which is a feature of biochemical substances. The FT-IR spectra of fresh and stored dried samples of six bacterial isolates (Klebsiellasp.,Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, Achromobacter xylosoxidans and Achromobactersp.) were observed by variation in sample preparation. The results indicated that variation in sample preparation did not affect the spectra of isolates. However, less promiment/absence of a small shoulder peak at 1738 cm−1was evident in fresh dried samples ofAchromobactersp. and A.xylosoxidanscompared to prominent and broad shoulder band at 1724 cm−1in stored dried samples of these two isolates. In addition to the established KBr pellet technique, attenuated total reflectance (ATR) spectroscopy was used to analyse the spectra of planktonic growth (−80°C liquid cultures) and biofilm growth of six isolates. ATR spectroscopy of −80°C planktonic and biofilm growth showed variation in absorption spectra in fingerprint (1200−900 cm−1) region. Two clear absorption bands were prominent in biofilm at 1175 and 1143 cm−1whereas, one prominent broad band at 1075 cm−1resulting from the overlapping of two band was noted in planktonic cultures. Biofilm forming capability of the six isolates was also determined by acridine orange staining method. The microscopic analysis of biofilms formed on glass slides revealed the presence of a matrix of exopolysaccharides and microcolonies typical of biofilm architecture. Maximum biofilm formation was observed after 175 h inP. aeruginosaandKlebsiellasp.

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Different solid sample preparation methods affecting the spectral similarity of salmon calcitonin

Spectroscopy An International Journal ◽

10.1155/2010/721325 ◽

2010 ◽

Vol 24 (5) ◽

pp. 511-516 ◽

Cited By ~ 2

Author(s):

Shan-Yang Lin ◽

Chih-Cheng Lin ◽

Ting-Huei Lee

Keyword(s):

Solid State ◽

Sample Preparation ◽

Conformational Changes ◽

Salmon Calcitonin ◽

Structural Similarity ◽

Preparation Methods ◽

Model Protein ◽

Ft Ir ◽

Ir Microspectroscopy ◽

Sample Preparation Methods

Salmon calcitonin (sCT) was selected as a model protein drug for investigating its structural similarity in the solid state by four sample preparation methods, such as tape, smeared, CaF2and film methods. The conformational changes of sCT in the solid state were estimated by using a second-derivative Fourier transform infrared (FT-IR) microspectroscopy. The tape method was acted as a standard reference.The value of correlation coefficient (r) for smeared method was higher than that of other method, indicating that a novel technique by smearing sCT powder on the surface of KBr pellet was the best optimal sample preparation method.

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Lignin Determination by FT-IR

Applied Spectroscopy ◽

10.1366/0003702924125456 ◽

1992 ◽

Vol 46 (2) ◽

pp. 246-248 ◽

Cited By ~ 21

Author(s):

Michael A. Friese ◽

Sujit Banerjee

Keyword(s):

Moisture Content ◽

Sample Preparation ◽

Infrared Spectrum ◽

Diffuse Reflectance ◽

Lignin Content ◽

Kappa Number ◽

Ft Ir ◽

Diffuse Reflectance Infrared ◽

Degree Of Overlap ◽

No Sample Preparation

The lignin content of pulp is determined from its diffuse reflectance infrared spectrum by an algorithm that calculates the degree of overlap between two spectra. The lignin:cellulose fraction correlates with kappa number, a titrimetric measure of lignin. Essentially no sample preparation is required, and the procedure is insensitive to variations in moisture content. The algorithm is able to detect changes induced by exposure of pulp to NO2.

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Influence of Sample Mixing Techniques on Engine Oil Contamination Analysis by Infrared Spectroscopy

Lubricants ◽

10.3390/lubricants7010004 ◽

2019 ◽

Vol 7 (1) ◽

pp. 4 ◽

Cited By ~ 2

Author(s):

Torrey Holland ◽

Ali Mazin Abdul-Munaim ◽

Dennis G. Watson ◽

Poopalasingam Sivakumar

Keyword(s):

Sample Preparation ◽

Limit Of Detection ◽

Critical Role ◽

International Standards ◽

Engine Oil ◽

Preparation Technique ◽

Stable Emulsion ◽

Ft Ir ◽

Ir Analysis ◽

The Impact

For the most reliable and reproducible results for calibration or general testing purposes of two immiscible liquids, such as water in engine oil, good emulsification is vital. This study explores the impact of emulsion quality on the Fourier transform infrared (FT-IR) spectroscopy calibration standards for measuring water contamination in used or in-service engine oil, in an attempt to strengthen the specific guidelines of ASTM International standards for sample preparation. By using different emulsification techniques and readily available laboratory equipment, this work is an attempt to establish the ideal sample preparation technique for reliability, repeatability, and reproducibility for FT-IR analysis while still considering the ease and efficiency of the technique. This study demonstrates that a stable emulsion within a sample, which depends heavily upon the method, provides a reliably consistent homogenous sample for quantification purposes with FT-IR analysis. Analysis of variance (ANOVA) modeling and limit of detection calculations demonstrate the stability of the emulsion. The results reveal that setting a mixing time for a calibration standard depends on the emulsification process. Inserting a probe directly into a sample (direct sonication) allows for a rapid, stable emulsion with high reproducibility. Indirect sonication produces relatively non-miscible liquids of different densities. The pan-shaker produces a reasonably stable emulsion, but without the long-term stability or quick production time of direct sonication. Reaction time plays a critical role in the rotary mixing method, which leads to a slow development of emulsification.

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Optimization of Sample Preparation Using Glass Slides for Spectral Pathology

Applied Spectroscopy ◽

10.1177/0003702820945748 ◽

2020 ◽

pp. 000370282094574

Author(s):

Lewis M. Dowling ◽

Paul Roach ◽

Abigail V. Rutter ◽

Ibraheem Yousef ◽

Srinivas Pillai ◽

...

Keyword(s):

Lung Cancer ◽

Sample Preparation ◽

Cancer Cells ◽

Lung Cancer Cells ◽

Thin Glass ◽

Glass Substrates ◽

Standard Clinical Practice ◽

Different Types ◽

Ft Ir ◽

Ir Microspectroscopy

The clinical translation of Fourier transform infrared (FT-IR) microspectroscopy in pathology will require bringing this technique as close as possible to standard practice in pathology departments. An important step is sample preparation for both FT-IR microspectroscopy and pathology. This should entail minimal disruption of standard clinical practice while achieving good quality FT-IR spectral data. In fact, the recently described possibility of obtaining FT-IR spectra of cells placed on glass substrates brings FT-IR microspectroscopy closer to a clinical application. We have now furthered this work in order to identify two different types of lung cancer cells placed on glass coverslips. Two types of sample preparation which are widely used in pathology, cytospin and smear, have been used. Samples were fixed with either methanol, used in pathology, or formalin (4% paraformaldehyde) used widely in spectroscopy. Fixation with methanol (alcohol-based fixative) removed lipids from cells causing a decrease in intensity of the peaks at 2850 cm−1 and 2920 cm−1. Nevertheless, we show for the first time that using either type of sample preparation and fixation on thin glass coverslips allowed to differentiate between two different types of lung cancer cells using either the lipid region or the fingerprint region ranging from 1800 cm−1 to 1350 cm−1. We believe that formalin-fixed cytospin samples would be preferred to study cells on thin coverslips using FT-IR microspectroscopy. This work presents a clear indication for future advances in clinical assessment of samples within pathology units to gain a deeper understanding of cells/tissues under investigation.

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Curcumin: Biological, Pharmaceutical, Nutraceutical, and Analytical Aspects

Molecules ◽

10.3390/molecules24162930 ◽

2019 ◽

Vol 24 (16) ◽

pp. 2930 ◽

Cited By ~ 36

Author(s):

Raghavendhar R. Kotha ◽

Devanand L. Luthria

Keyword(s):

Clinical Trials ◽

Sample Preparation ◽

Biological Activities ◽

Aqueous Solubility ◽

Detailed Comparison ◽

In Vivo Studies ◽

Ft Ir ◽

Ft Raman

Turmeric is a curry spice that originated from India, which has attracted great interest in recent decades because it contains bioactive curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin). Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione), a lipophilic polyphenol may work as an anticancer, antibiotic, anti-inflammatory, and anti-aging agent as suggested by several in vitro, in vivo studies and clinical trials. However, poor aqueous solubility, bioavailability, and pharmacokinetic profiles limit curcumin’s therapeutic usage. To address these issues, several curcumin formulations have been developed. However, suboptimal sample preparation and analysis methodologies often hamper the accurate evaluation of bioactivities and their clinical efficacy. This review summarizes recent research on biological, pharmaceutical, and analytical aspects of the curcumin. Various formulation techniques and corresponding clinical trials and in vivo outcomes are discussed. A detailed comparison of different sample preparation (ultrasonic, pressurized liquid extraction, microwave, reflux) and analytical (FT-IR, FT-NIR, FT-Raman, UV, NMR, HPTLC, HPLC, and LC-MS/MS) methodologies used for the extraction and quantification of curcuminoids in different matrices, is presented. Application of optimal sample preparation, chromatographic separation, and detection methodologies will significantly improve the assessment of different formulations and biological activities of curcuminoids.

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